Heating configuration for a drier

ABSTRACT

A heating configuration for a drier, particularly a laundry drier, has a burner with a burner head, a first heating channel with an inlet opening and an outlet opening, and a second heating channel with an inlet opening and an outlet opening. The cross-sectional area of the second heating channel is greater than the cross-sectional area of the first heating channel. The burner projects through its inlet opening into the first heating channel and an outlet portion of the first heating channel projects into an inlet portion of the second heating channel. A guide device is provided in an upper section of the first heating channel adjacent to the outlet opening thereof in order to downwardly deflect hot gases which flow from the burner head in a direction towards the outlet opening of the second heating channel.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to heating configuration for a drier,particularly for a laundry drier.

U.S. Pat. No. 1,311,235 discloses a gas burner having a burner headwhich projects through an inlet opening of a heating channel. An annularopening between the inlet opening and the burner serves as an air entry.The distal end of the heating channel projects by an outlet openingthereof into an inlet of a further heating channel having a greaterdiameter than the first heating channel. An annular area between thefirst heating channel and the further heating channel serves as afurther air entry opening.

The prior art configuration of burner and heating channels isdisadvantageous in that the temperature distribution is non-uniform inthe channels.

There is therefore a need for a heating configuration for a drier,particularly for a laundry drier, in which the temperature distributionin the heating channel is as uniform as possible so that a more reliableoperation of the heating configuration is ensured and improvedtemperature regulation is possible.

SUMMARY OF THE INVENTION

It is accordingly an object of the invention to provide a heatingconfiguration for a drier which overcomes the above-mentioneddisadvantages of the heretofore-known devices and methods of thisgeneral type.

With the foregoing and other objects in view there is provided, inaccordance with the invention, a heating configuration for a drier, suchas a laundry drier, comprising:

-   -   a burner with a burner head;    -   a first heating channel having an inlet portion formed with an        inlet opening and an outlet portion formed with an outlet        opening;    -   a second heating channel having an inlet portion formed with an        inlet opening and an outlet portion formed with an outlet        opening;    -   the second heating channel having a cross-sectional area greater        than a cross-sectional area of the first heating channel, the        outlet portion of the first heating channel projecting into the        inlet portion of the second heating channel, and the burner        projecting into the first heating channel through the inlet        opening thereof; and    -   a flow guide in an upper part of the first heating channel        adjacent the outlet opening thereof and configured to downwardly        deflect a flow of gas flowing in a direction from the burner        head towards the outlet opening of the second heating channel.

Preferably, the burner head is disposed in the first heating channel.

In other words, according to the present invention there is providedheating configuration for a drier, particularly a laundry drier, thathas a gas burner with a burner head, a first heating channel with aninlet opening and an outlet opening and a second heating channel with aninlet opening and an outlet opening and a cross-sectional area which isgreater than the cross-sectional area of the first heating channel,wherein the burner head projects into the inlet opening of the firstchannel and the outlet opening of the first heating channel projectsinto the inlet opening of the second heating channel, a guide devicebeing provided in the upper section of the first heating channeladjacent to the outlet opening thereof in order to downwardly deflecthot gases which flow from the burner head in direction to the outletopening of the second heating channel.

Due to the fact that the heating configuration has a guide device in theupper section of the first heating channel adjacent to the outletopening thereof, whereby hot gases which flow from the burner head indirection towards the outlet opening of the second heating channel aredeflected downwardly, it is thereby possible to guide hot air or hotgases, which flows or flow out of the first heating channel and whichdue to air lift has or have a tendency to flow upwardly, into the middlesection of the second heating channel so that overheating of the uppersection of the second heating channel is avoided. Through provision ofthe guide device it is therefore possible to achieve a more uniformtemperature distribution over the cross-sectional area. Moreover,supplementary air, which due to the provision of the guide device in theupper section of the first heating channel is better mixed with hotgases flowing out of the first heating channel, enters the secondheating channel between the outlet opening of the first heating channeland the inlet opening of the second heating channel. Due to the bettermixing of the supplementary air and the hot gases flowing out of thefirst heating channel and thus a more uniform temperature distributionover the cross-section of the second heating channel, hot zones withinthe second heating channel are avoided, which ensures a more reliableoperation of the heating configuration. By virtue of the uniformtemperature distribution in this heating channel arrangement a moreprecise detection of the temperature of the gases disposed in theheating channel arrangement is possible so that a more precisetemperature regulation can be undertaken.

In accordance with an advantageous feature of the invention, the guidedevice is constructed as an inclined wall which extends at a downwardslope in flow direction from a middle upper section of the first heatingchannel to the outlet opening of the first heating channel. A flame thatissues from the burner and has already mixed with first supplementaryair which has entered between the burner and the inlet opening of thefirst heating channel is thereby conducted downwardly in the outletregion of the first heating channel. This is advantageous, since theflame issuing from the burner head flows upwardly due to heat lift andis conducted downwardly at the end of the first heating channel by theguide device.

In accordance with an preferred feature of the invention, the inclinedwall is integrated in the end section of the first heating channel. Thisis particularly advantageous when the heating channel is made of sheetmetal so that for formation of the guide device it is merely necessaryto downwardly indent the upper end section adjacent to the outletopening of the first heating channel by means of a stamping device. Aparticularly simple and advantageous construction of the guide device isthereby provided. Moreover, through construction of the guide device inthat manner the inlet opening for supplementary air between the firstheating channel and the second heating channel is enlarged in the regionof the guide device so that supplementary air can flow in more easilyand thus in greater quantity in this region. The upper side of thesecond heating channel is thus supplied with more supplementary air,which counteracts overheating of the upper side of the second heatingchannel.

Preferably, the first heating channel is arranged in the lower sectionof the second heating channel. The first heating channel is thereforearranged at the second heating channel to be eccentrically offsetdownwardly, so that the air entry opening for supplementary air betweenthe first heating channel and the second heating channel is formedprincipally at the upper side of the second heating channel. Due to thismeasure it is possible for hot gases, which issue from the first heatingchannel and which due to heat lift preferentially flow upwardly in theupper region of the second heating channel, to better mix withsupplementary air so that the effect of improved intermixing and moreuniform temperature distribution is reinforced by introduction of thefirst heating channel into the lower section of the second heatingchannel. In an advantageous embodiment the front lower section of thefirst heating channel is connected with the rear lower section of thesecond heating channel by fastening elements.

In accordance with an additional feature of the invention, the burner isarranged in the lower section of the first heating channel. The hotflame which issues from the burner head and which equally has a tendencyto flow upwardly due to heat lift, is thereby better retained in themiddle section of the first heating channel upstream of the burner headand better mixed with the supplementary air entering between the burnerand the inlet opening of the first heating channel. A more uniformdistribution is thereby achieved in the first heating channel.

For preference there is arranged at the outlet opening of the secondheating channel a deflection channel by which the hot gases aredeflected upwardly. This deflection channel preferably has an inclinedplane which extends obliquely upwardly from the lower middle section ofthe deflection channel in flow direction. By virtue of this inclinedplane a form of baffle plate is provided, at which the hot gases or thehot air is or are not only deflected upwardly, but also mixed moreuniformly over the cross-section.

Overall, formation of hot ‘temperature strands’ and hot airstratification and hot regions are avoided in the afore-describedheating configuration.

In an advantageous embodiment an air conveying device is arrangeddownstream of the outlet opening of the second heating channel in orderto provide conveying of the air from the burner in direction towards thedeflection channel.

Other features which are considered as characteristic for the inventionare set forth in the appended claims.

Although the invention is illustrated and described herein as embodiedin a heating configuration for a drier, it is nevertheless not intendedto be limited to the details shown, since various modifications andstructural changes may be made therein without departing from the spiritof the invention and within the scope and range of equivalents of theclaims.

The construction and method of operation of the invention, however,together with additional objects and advantages thereof will be bestunderstood from the following description of specific embodiments whenread in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a heating configuration for a drieraccording to the invention;

FIG. 2 is a side view of the heating configuration of FIG. 1;

FIG. 3 is a plan view of the heating configuration of FIG. 1; and

FIG. 4 is a cross-section along the line IV-IV in FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the figures of the drawing in detail and first,particularly, to FIG. 1 thereof, there is shown a heating configurationcomprising a burner 1 with a burner head 2, a first heating channel 3, asecond heating channel 4 and a deflection channel 5. The first heatingchannel 3 is a cylindrical or possibly oval pipe section made of sheetmetal and formed with an inlet opening 6 and an outlet opening 7. Thesecond heating channel 4 is a cylindrical pipe length 9 which is made ofsheet metal and has an inlet opening 10 and an outlet opening 11. Thefirst heating channel 3 has a smaller diameter than the second heatingchannel 4. The first heating channel 3 projects by an outlet portionthereof in overlapping manner into an inlet portion of the secondheating channel and the first heating channel 3 is arranged on theunderside of the second heating channel 4 and connected therewith. Theburner 1 projects into the inlet portion of the first heating channel 3in such a manner that the burner head 2 is arranged in the lowersection, thus below a centerline 12, of the first heating channel 3.

An approximately circular first air entry opening 13, by way of whichfirst supplementary air 14 can enter the first heating channel 3, isformed between the burner 1 and the perimeter of the inlet opening 6 ofthe first heating channel. Adjacent to the outlet opening 7 of the firstheating channel 3 and at the upper end section of the first heatingchannel 3 there is provided a guide device 15 which forces the hot airor gases, which flows or flow through the first heating channel 3,downwardly in the region of the outlet opening 7 of the first heatingchannel 3 so that the hot air or gases enters or enter the lower portionof the second heating channel 4. The guide device 15 is formedintegrally with the cylindrical pipe length 8 of the first heatingchannel in that an upper end section of the cylindrical pipe section 18is deformed into a slightly concave indentation 16 by means of astamping process or bending process. The indentation has an inclinedwall 16 a which extends at a downward inclination in flow direction 20from a middle upper length section of the first heating channel 3 to theoutlet opening 7 of the first heating channel 3.

A second, crescent-shaped air entry 17, which is enlarged in the regionof the indentation 16, is formed between the perimeter of the outletopening 7 of the first heating channel 3 and the perimeter of the inletopening 10 of the second heating channel 4 (FIG. 4).

The deflection channel 5, which initially has a substantially squarecross-section and which is increasingly rectangular up to an upwardlydirected outlet opening 18 thereof, is hermetically connected with theoutlet opening 11 of the second heating channel 4. The deflectionchannel 5 has an inclined plane 19, which extends obliquely upwardlyfrom the lower middle section of the deflection channel 5 in flowdirection 20. An air conveying device 22 is disposed downstream(relative to the flow direction) of the outlet opening 18 of thedeflection channel 5. The air conveying device 22 conveys air throughthe channels in flow direction 20.

Due to the burner head being arranged in the lower section of the firstheating channel 3, the guide device 15 in the form of the indentation 16being provided at the upper end section adjacent to the outlet opening 7of the first heating channel 3 and the first heating channel beingarranged eccentrically in the lower section of the second heatingchannel 4, the flame or the hot air or hot gases which mixes or mixtherewith and which always has or have a tendency to migrate upwardlydue to thermal lift and thus excessively heat the upper sections of thefirst and second heating channel, is or are forced downwardly in eachsection of the heating configuration or kept in a middle section of thefirst heating channel 3 or the second heating channel 4. The entireheating configuration, but particularly the first heating channel 3 andthe second heating channel 4, is preferably arranged horizontally.However, it is also possible to arrange the heating configuration toextend upwardly at a preferred angle of up to 45° together with thedeflection channel 5.

By virtue of the afore-described heating configuration an improvedmixing of the gases is achieved, which has the consequence of a moreuniform temperature distribution over the flow cross-section. With amore uniform temperature distribution, there is also possible a moreprecise detection of the temperature of the gases flowing in the heatingconfiguration so that a more exact setting or regulation of thetemperature of the gases is possible.

The first supplementary air 14 is fed in a first air stream from behindthe burner by way of the first air entry opening 13. Secondsupplementary air 21 is fed into the heating configuration in a secondair stream by way of the second air entry opening 17. This feed of firstsupplementary air 14 and second supplementary air 21 has the advantagethat in the region of the burner only a part of the air quantityrequired for drying has to flow through the first heating channel 3, sothat the burner readily ignites and exhibits good flame formation.Lifting-off of the flame of the burner is thereby prevented and as aconsequence combustion noise is avoided. In addition, CO emission andemission of unburned fuel due to the lesser amount of cooling areavoided.

The burner burns with a relatively short and voluminous flame in thefirst heating channel 3. This leads to good intermixing of the hotexhaust gases with the cold, first supplementary air 14 is produced.

This application claims the priority, under 35 U.S.C. § 119, of Germanpatent application No. 103 32 339.2, filed Jul. 16, 2003; the entiredisclosure of the prior application is herewith incorporated byreference.

1. A heating configuration, comprising: a burner with a burner head; afirst heating channel having an inlet portion formed with an inletopening and an outlet portion formed with an outlet opening; a secondheating channel having an inlet portion formed with an inlet opening andan outlet portion formed with an outlet opening; said second heatingchannel having a cross-sectional area greater than a cross-sectionalarea of said first heating channel, said outlet portion of said firstheating channel projecting into said inlet portion of said secondheating channel, and said burner projecting into said first heatingchannel through said inlet opening thereof; and a flow guide in an upperpart of said first heating channel adjacent said outlet opening thereofand configured to downwardly deflect a flow of gas flowing in adirection from said burner head towards said outlet opening of saidsecond heating channel.
 2. The heating configuration according to claim1, wherein said burner head is disposed in said first heating channel.3. The heating configuration according to claim 1, wherein said flowguide comprises an inclined wall extending with a downward slope in thedirection from said upper part of said first heating channel betweensaid inlet and outlet openings thereof to said outlet opening of saidfirst heating channel.
 4. The heating configuration according to claim3, wherein said inclined wall is an inwardly deformed portion of a wallof said first heating channel.
 5. The heating configuration according toclaim 1, wherein said outlet portion of said first heating channel isdownwardly offset towards a lower side of said second heating channel.6. The heating configuration according to claim 1, wherein a part ofsaid burner projecting into said first heating channel is disposedsubstantially in a lower part of said first heating channel.
 7. Theheating configuration according to claim 1, wherein a first air entry isformed between a perimeter of said inlet opening of said first heatingchannel and said burner, and a second air entry is formed between aperimeter of said inlet opening of said second heating channel and aperimeter of an outlet portion of said first heating channel.
 8. Theheating configuration according to claim 1, which further comprises adeflection channel connected to said outlet opening of said secondheating channel and disposed to upwardly deflect gases flowing from saidsecond heating channel.
 9. The heating configuration according to claim8, wherein said deflection channel has an inclined surface extendingobliquely upwardly from a lower side of said deflection channel.
 10. Theheating configuration according to claim 1, which comprises an airconveying device disposed downstream of said outlet opening of saidsecond heating channel with respect to a direction of a flow of gasesout of said second heating channel.
 11. The heating configurationaccording to claim 1, wherein said outlet portion of said first heatingchannel has a base portion connected to a base portion of said inletportion of said second heating channel.
 12. The heating configurationaccording to claim 1, wherein said burner and said heating channels areconfigured for assembly in a drier apparatus.
 13. In combination with alaundry drier, the heating configuration according to claim 1.